The invention relates to a hygienic disposable article made from wood-pulp of the type configured for use as a diaper, having a linen-protecting sheet, a porous covering of non-woven material arranged to face the wearer's body, and an absorbent body arranged between the protecting sheet and the porous covering extending from the crotch area to the waist area, the absorbent body being composed of a mixture of wood-pulp fibers fibers and expandable materials, and further having a reinforcement area arranged in the crotch area, along the longitudinal axis of the diaper.
An absorbent body with expandable materials which are uniformly embedded in the absorbent body is already known from European Patent EP-A-O No. 157,649. As a result of the reinforcing of the center, it is true that a definite quantitative concentration is achieved in the crotch area; however, there does not ensue an optimal adaptation of these super-absorbent expandable materials to the actual distribution of the accumulating fluid. Likewise, such a uniform distribution of the expandable materials in the absorbent body has the disadvantage that in the end-areas of the diaper there are located large quantities of expandable materials which may not be effectively used; on the other hand, in manufacturing, they operate disadvantageously insofar as they cause blunting of the cutter blades. Also, in the end-areas of the diaper, those expandable materials that are present as granules escape from the diaper.
Especially suitable as expandable materials are polymers that form hydrogels, as they are described in European Patent EP-A-O No. 205,674. These are highly expandable polymers which expand slowly upon the entry of a fluid and which store up fluid in large volume.
The basic objective of the invention is to provide for an optimal distribution of the absorbent components of the diaper, corresponding in large measure to the distribution pattern of the fluid as it prevails in the diaper and presenting an optimal characteristic curve of fluid uptake. In this way, an economical use of the specified quantity of expandable materials is facilitated by concentrating them precisely where, in actual experience, the most copious fluid accumulation occurs in the diaper.